The constant part of the viscous stress tensor manifests itself as a kind of pressure, that acts equally and perpendicularly on any surface independent of its orientation.
12.
More precisely, a fluid is Newtonian only if the tensors that describe the viscous stress and the strain rate are related by a constant compression or expansion, respectively.
13.
The viscous stress tensor is formally similar to the elastic stress tensor that describes internal forces in an total stress tensor comprises both viscous and elastic ( " static " ) components.
14.
The role of the tangential viscous stress is essential in establishing a steady meniscus shape in flow focusing, as illustrated in the case of a simple liquid jet surrounded by a gas.
15.
Thus, the linear models represented by the tensors and are almost always sufficient to describe the viscous stress and the strain rate around a point, for the purpose of modelling its dynamics.
16.
This part of the viscous stress, usually called bulk viscosity or volume viscosity, is often important in viscoelastic materials, and is responsible for the attenuation of pressure waves in the medium.
17.
The structural damping law implies that frictional losses are coupled tightly to elastic stresses rather than to viscous stresses, but the precise molecular mechanical origin of this phenomenon remains unknown ( 1, 2 ).
18.
In an arbitrary coordinate system, the viscous stress and the strain rate at a specific point and time can be represented by 3 ?3 viscosity tensor such that " ?E " } }.
19.
According to Van Dyke, quoted in Lift ( force ) Wikipedia article, ?0.3, the derivation of his equation ( 4c ) also shows that the contribution of viscous stress to flow turning is negligible.
20.
While the viscous stresses are generated by physical phenomena that depend strongly on the nature of the medium, the viscous stress tensor is only a description the local momentary forces between adjacent parcels of the material, and not a property of the material.
